This clinical trial studies 4-dimensional (4-D) image-guided radiation therapy treatment planning in patients with stage I-IV non-small cell lung cancer. Computed tomography (CT) scans and treatment-planning systems may help in planning radiation therapy for patients with non-small cell lung cancer. This is not a therapy study. Therefore no direct benefit from participating is expected. However, at the discretion of the treating physician, the information gained from the additional imaging will be used to improve treatment accuracy. No patient outcome data are gathered or analyzed by this study. This study is not a:Phase I, II, or III trial, trial with "blinded" treatment arm, gene or a vaccine trial, or a multi-institutional trial.